RNA sequencing reveals differential MYC-driven gene expression as a driver of a divergent cholangiocyte response to stress

In Primary Sclerosing Cholangitis (PSC), some cholangiocytes undergo cell cycle arrest (senescence) while others proliferate (ductular reaction). Our aim was to determine the mechanisms driving this divergent response. We used lipopolysaccharide (LPS) to stress normal human cholangiocytes (NHC) transfected with a senescence reporter, p16- promoter driven green fluorescent protein. We performed RNA sequencing to assess gene expression profiles on non-senescent (GFP-) and senescent (GFP+) cholangiocytes. Our analysis revealed a MYC-driven gene expression profile in non-senescent cholangiocytes and suggest that MYC may function as a "molecular switch" in determining cholangiocyte responses to stress. Overall design: NHCs were stably transfected with a p16-promoter driven green fluorescent protein (GFP) reporter (p16-GFP-NHC) and cultured in the presence or absence of the cellular stressor LPS in our in vitro model of experimentally induced NHC senescence. The cells were collected and standard fluorescence activated cell sorting (FACS) analysis was performed. We then performed RNA sequencing analysis on the non-senescent (GFP-) and senescent (GFP+) cell populations.